U.S. Bureau of Labor Statistics

Office of Survey Methods Research

Abstract

The Current Population Survey (CPS), a national survey of
60,000 households, is a major source of information about the
American labor market. In January 1994, the CPS underwent a
major redesign both in the wording of the questionnaire and
the methodology used to collect the data. The objective of
the redesign was to improve the quality and expand the
quantity of available data. However, the redesign also caused
changes in the measurement of many of the estimates derived
from the CPS. To assess the effect of the redesign a parallel
survey was conducted in two phases. During the first phase,
data were collected using the revised questionnaire and
collection methodology. In the second phase of the parallel
survey, data were collected using the unrevised questionnaire
and procedures. Using monthly data from the parallel survey
and the CPS conducted during the same time period, this paper
estimates adjustment factors for various aggregate measures
derived from the CPS in order to permit comparisons of
estimates before and after the redesign. The adjustment
factors are estimated using a main effects linear model and
generalized least squares. These adjustment factors indicate
that the redesign had no statistically significant effect on
the total unemployment rate, but it did affect statistics
related to unemployment such as the reasons for unemployment,
the duration of unemployment and the industry and occupation
distribution of the unemployed with previous work experience.
The adjustment factors also indicate that the redesign
significantly increased the employment-to-population ratio
and labor force participation rate for women, but
significantly decreased the employment-to-population ratio
for men. At the same time the redesign significantly
influenced the measurement of characteristics related to
employment such as the proportion of employed working part
time, the proportion working part time for economic reasons,
the number of individuals classified as self-employed and the
industry and occupation distributions of the employed.